Hello,
We have a system with 5 Gemini 2 cameras triggered through an Orbbec Star hub. We’re trying to trigger 4 of those using the fifth as the trigger source into the primary port of the hub. All 5 cameras are connected to the computer through a USB3.0 hub, which is powered by an external power supply; the power to the Star hub comes through the USBC port. We’re running a C++ program compiled with gnu g++ (12.3.0) on Ubuntu 22.04, based on the Orbbec MultiDeviceSync example. We’re capturing both depth and color camera images, except where otherwise noted below. Each time we trigger, we wait for data to be received from all cameras before sending the next trigger, so when we get an exception, the program hangs.
What we’re seeing is that everything works fine with up to 3 Gemini cameras connected. If we do not enable the depth channel stream, it works fine with 4 cameras. If we enable either both depth + color or depth only streams, we see the problem described below.
With 4+ cameras connected, we may successfully trigger and capture images once or twice, but then we get the error
[02/08 10:38:23.523736][warning][1038433][FrameUnpacker.cpp:215] RLE decode error, frame data size too large!
[02/08 10:38:23.523786][warning][1038433][FrameUnpacker.cpp:235] Current frame data size error after RLE Decode, size=1791980, require=1792000
[02/08 10:38:23.523799][warning][1038433][FrameUnpacker.cpp:349] Frame Unpack failed due to original data is wrong! There may be interference in the device or data transmission.
Sometimes it doesn’t give the RLE decode error, but generally gives the frame data size and unpack errors. The process then hangs waiting for callbacks from all cameras after successfully grabbing images from only one, two, or even three of them. Occasionally, after failing in this way, one of the cameras disappears, and subsequent runs recognize only 3 of the 4 cameras until power is cycled (through disconnecting and reconnecting the USB hub).
Any insight into what might be causing this behavior would be appreciated.